AB0594 CLINICAL SIGNIFICANCE OF ANTI-LA ANTIBODIES IN SYSTEMIC LUPUS ERYTHEMATOSUS
Authors: C. Sanguesa, A. Olive, I. Rua-Figueroa, N. Jiménez, M. Galindo-Izquierdo, J. Calvo-Alen, R. Menor-Almagro, A. Fernandez-Nebro, E. Uriarte Isacelaya, E. Aurrecoechea, N. Mena-Vázquez, J. M. Senabre-Gallego, J. Narváez, A. Pérez Gómez, J. L. Andreu, E. Tomero Muriel, G. Bonilla, T. Cobo-Ibáñez, C. Moriano, M. J. Garcia Villanueva, E. Salgado Perez, N. Lozano Rivas, A. Pecondon-Español, J. Eloy Oller, J. Loricera, T. C. Salman Monte, F. J. Nóvoa Medina, C. A. Montilla-Morales, E. Ruiz Lucea, J. J. Fragío Gil, A. Muñoz Jimenez, M. Arévalo, J. M. Pego-Reigosa
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Systemic lupus erythematosus (SLE) is a systemic autoimmune disease characterized by a wide spectrum of clinical manifestations and the presence of various antibodies against antigens of the nucleus, cytoplasm, or membrane cell. Anti-La antibodies are present in 7-45% of SLE patients, usually accompanied by anti-Ro antibodies. Double anti-La and anti-Ro positivity is associated with a milder disease profile, with a lower risk of seizures and nephritis, as well as a higher frequency of arthritis. Studies analyzing the prevalence and clinical characteristics of patients with isolated anti-La+ in the absence of anti-Ro are lacking. <h3>Objectives</h3> To describe the demographic, clinical and serological characteristics and severity indices of anti-Ro-/La+ patients in a retrospective cohort of SLE patients and compare them with the rest of the patients. <h3>Methods</h3> Retrospective cross-sectional study, in which all patients with SLE (&gt; 4 ACR-1997 criteria) registered in the RELESSER registry were included. Sociodemographic, clinical, serological and comorbidities variables were collected, as well as indicators of disease activity and severity. Patients were divided into 4 groups according to the presence of anti-Ro and anti-La: anti-Ro-/La+ group, anti-Ro+/La- group, anti-Ro+/La+ group and anti-Ro-/La- group. The anti-Ro-/La+ group was compared with the other groups. <h3>Results</h3> Out of 3619 SLE patients, 44 (1.2%) had anti-Ro-/La+. The mean (± SD) age was 33.77 (±16.52) years, 88.6% were female, 90.5% were Caucasian and the mean (± SD) disease duration was 135.36 (±88.46) months. The most frequent comorbidities were: smoking 48.8 %, dyslipidaemia 47.7 % and hypertension 31.8 %. 22.13% of patients had anti-Ro+/La-, 18.98% anti-La+/Ro+ and 64.02% anti-La-/Ro-. Photosensitivity and oral ulcers were observed more frequently in anti-Ro-/La+ patients compared to anti-Ro-/La- patients (60.2% vs 52.6% p=0.0471 and 59.1% vs 40.7% p=0.0194 respectively). Arthritis occurred in 77.3% of anti-Ro-/La+ patients, without significant differences with the other groups: 75.3% in anti-Ro+/La- (p=0.8588), 73.9% in anti-Ro+/La+ (p=0.7240) and 75.1% in anti-Ro+/La- (p=0.810). Twenty-five per cent of patients with isolated anti-La had lupus nephritis, with no significant differences compared to the other groups (29.5% in anti-Ro+/La- p=0.6116, 22.9% in Ro+/La+ p=0.7144 and 28.6% in Ro-/La- p=0.7364). 11.4% of anti-Ro-/La+ patients had seizures vs 4.4% anti-Ro+/La-(p=0.0510), vs 3.3% in anti-Ro+/La+ (p=0.0218) and vs 5.2 % in anti-Ro-/La- (p=0.799). Cognitive impairment was observed in 7% of anti-Ro-/La+ patients vs 2.8% in anti-Ro+/La- (p=0.1315) vs 1.5% in anti-Ro+/la+ (p=0.0370) and vs 3.1% in anti-Ro-/La- (p=0.1492). No differences were observed in other SLE-associated clinical variables, immunological profile, degree of SLE activity or Katz severity index. <h3>Conclusion</h3> The prevalence of anti-La in the absence of anti-Ro in our SLE cohort was 1.2%. This group of patients presented a higher frequency of clinical manifestations such as photosensitivity and oral aphthous ulcers compared to patients with neither anti-Ro nor anti-La. In contrast with previous studies the isolated presence of anti-La is associated with greater neurological involvement in the form of seizures or cognitive impairment compared to the association of anti-Ro and anti-La or the isolated presence of anti-Ro. <h3>REFERENCES:</h3> NIL. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.